The effect of dolomite stone powder content on the rheological behavior of cement based materials by fluidity of cement paste and the torque parameter of mortar was studied. The action mechanism of stone powder on rheological properties was investigated systematically by testing the water demand, the adsorption behavior and the Zeta potential. The results show that the fluidity of cement paste increases and torque of motar decreases with the increase content of dolomite stone powder, and the fluidity of cement paste increases more significantly when the content of dolomite stone powder exceeds 12%. The water demand ratio of mortar with dolomite stone powder is 93%, which indicates that the water demand of the dolomite stone powder is smaller than that of cement, and it will lead to the better flow properties of cement paste by inclusion of the stone powder. TOC results show that there exists a competitive adsorption of polycarboxylate superplasticizer(PCE) on dolomite stone powder and the cement surface. The adsorption ability of PCE on dolomite stone powder surface is weaker, so the adsorption of dolomite stone powder is also one of the reasons for increasing the rheological properties of cement paste or mortar. The zeta potential value on surface of pure cement particles and stone powder particles is -176mV and -894mV, respectively, which indicate that the cement and stone powder have different adsorption capacity for PCE. PCE will be preferentially adsorbed on the surface of cement particles.